I have been using the Channel Master CM-7777 for a year now and it has been a stellar performer. It is the only pre-amp on the market, AFAIK, that claims a 30 db gain. I happen to need that kind of gain and it seems to perform properly with an Antennas Direct 91XG even though I have a TV transmitter 90 degrees off axis 5 miles away and a cell repeater a block away.
I'm posting here because I received a new product notice from Channel Master showing a redesigned pre-amp
CM-7777HD which now includes a low-pass filter to eliminate interference from cellular telephone signals above 800 MHz. They also now have a separate
in-line low-pass filter to retrofit existing installations.
Ken